Conventionally, illumination devices including a light-transmitting cover member (e.g., a transparent or semi-transparent cover member) which encloses a light source so as to cover the light source have been widely used. Examples of this kind of illumination device encompass electrical bulbs, electrical lamps, etc. using a variety of light sources such as LEDs, filaments, and cold cathode tubes.
For example, Patent Literature 1 discloses a lamp including a member which has a peripheral wall and a light source attachment section that are integrally molded from aluminum. The peripheral wall has a cylindrical shape, and the light source attachment section is disposed so as to close one end of the peripheral wall in an axial direction of the peripheral wall. The member is provided with a cover attachment groove at a portion where the peripheral wall and the light source attachment section are integrally continuous with each other (along a periphery of the light source attachment section). The cover attachment groove has a circular shape and is exposed to an outside. A light source cover is attached to the member by fitting a circular opening edge of the light source cover to the cover attachment groove and bonding them with the use of an adhesive.